* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Fractions, Decimals, and Percents
Survey
Document related concepts
Transcript
Fractions, Decimals, and Percents Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. ____ ____ 1. Write 1.166 in expanded form. a. 1 + 0.1 + 0.6 + 0.6 c. 1 + 0.1 + 0.06 + 0.006 b. 1 + 1 + 6 + 6 d. 1 + 0.01 + 0.006 + 0.0006 2. Write 4 + 0.6 + 0.05 + 0.009 in standard form. a. 4.6509 c. 4.0659 b. 40.659 d. 4.659 3. Write 11.2 in words. a. two tenths c. eleven and two hundredths b. eleven and two tenths d. two hundredths 4. Order the following decimals from least to greatest. 2.518, 2.287, 2.611 a. 2.287, 2.518, 2.611 c. 2.518, 2.287, 2.611 b. 2.287, 2.611, 2.518 d. 2.611, 2.287, 2.518 5. Find the product. 4.17 • 4.6 a. 8.77 c. 19.182 b. 191.82 d. 1.9182 6. Find the quotient. ____ a. 0.234 b. 2.34 7. Divide. ____ ____ ____ ____ ____ c. 23.4 d. 2.68 a. 0.098 c. 9.8 b. 0.98 d. 1.020408163265 8. Write the decimal 2.32 as a fraction or mixed number. a. 2 8 c. 1 25 b. 16 d. 2 3 10 8 25 ____ 9. Write the number 1 8 as a decimal. a. 18 c. 0.09 b. 0.125 d. 0.08 ____ 10. Order the fractions and decimals from least to greatest. 0.58, 0.8, a. 2 3 2 3 , 0.58, 0.8 b. 0.58, 2 , 0.8 3 ____ 11. Find two equivalent fractions for . c. 0.8, 2 , 0.58 3 d. 0.58, 0.8, 2 3 a. and c. and b. and d. and ____ 12. Find the missing number that makes the fractions equivalent. a. 8 b. 12 c. 6 d. 2 ____ 13. Write the fraction in simplest form. a. c. b. d. 5 1 ____ 14. Order 6 , 5 , and a. 1 b. 3 5 , 4, 1 5 , 6, 5 3 4 from least to greatest. c. 5 6 d. 3 4 5 3 6 , 4, 3 1 4 , 5, 1 5 5 6 ____ 15. Subtract, and write the answer in simplest form. 7 38 – 5 8 a. 1 15 16 c. 4 1 2 b. 3 1 4 d. 1 5 8 ____ 16. Multiply a. . Write the answer as a mixed number in simplest form. c. 1 18 2 3 b. 3 1 6 d. 1 2 ____ 17. Multiply the fractions, and simplify if possible. 1 • 8 5 7 a. c. 5 29 b. 5 56 d. 7 40 47 56 ____ 18. Multiply the fractions, and simplify if possible. 4 15 7 9 a. 2 26 45 c. 2 11 35 b. 1 2 5 d. 1 38 59 ____ 19. Multiply the mixed numbers, and simplify if possible. 1 2 22 17 a. 3 11 14 c. 3 3 14 b. 1 17 18 d. 2 1 7 ____ 20. Divide, and simplify if possible. 1 1 13 14 a. c. 1 1 15 15 16 b. d. 1 2 3 3 5 ____ 21. Evaluate a. 1 5 + 8. 5 11 c. 34 d. 4 13 b. 39 33 40 5 2 2 ____ 22. Evaluate 2 3 – 1 5 . a. 1 4 15 c. 1 3 16 b. 1 d. 1 1 3 3 7 ____ 23. Evaluate 2 7 – 1 12 . a. c. b. d. 71 84 71 83 ____ 24. Write 30% as a fraction in simplest form. a. 0.3 c. 10 3 b. 1 10 d. 3 3 10 ____ 25. Write 96% as a decimal. a. 0.96 c. 24 25 b. 1.04 ____ 26. Write the decimal 0.08 as a percent. a. 2 d. 9.6 c. 0.8% 25 b. 8% ____ 27. Write the fraction d. 0.0008% 2 5 as a percent. a. 250% b. 4% ____ 28. Find 20% of 35. a. 700 b. 7 Graph each number on a number line. 3 ____ 29. 1 4 c. 40% d. 0.4% c. 175 d. 10.4 a. c. –5 –4 –3 –2 –1 0 1 2 3 4 5 b. –5 –4 –3 –2 –1 0 1 2 3 4 5 –5 –4 –3 –2 –1 0 1 2 3 4 5 –5 –4 –3 –2 –1 0 1 2 3 4 5 –5 –4 –3 –2 –1 0 1 2 3 4 5 d. –5 –4 –3 –2 –1 0 1 2 3 4 5 ____ 30. 1.75 a. c. –5 –4 –3 –2 –1 0 1 2 3 4 5 b. d. –5 –4 –3 –2 –1 0 1 2 3 4 5 Find a fraction equivalent to the given fraction. ____ 31. a. c. b. d. a. c. b. d. ____ 32. ____ 33. Write as a mixed number in simplest form. a. 8 4 7 c. 8 5 7 b. 7 5 7 d. 7 6 7 5 ____ 34. Write 5 6 as an improper fraction. a. 35 c. 29 d. 6 6 b. 6 8 3 ____ 35. Write the fraction 1 as a decimal. Round to the nearest hundredth if necessary. a. 0.47 c. 0.27 b. 3.11 d. 3.67 ____ 36. Write the decimal 6.64 as a mixed number in simplest form. a. c. 6 16 25 b. ____ 37. Which decimal is less than –3.79? a. –3.78 b. –3.689 d. 6 16 25 c. –3.7889 d. –3.801 ____ 38. Order the numbers from least to greatest. 1 –1.656, –1.75, 1 2 a. –1.656, –1.75, 1 1 2 c. –1.75, –1.656, 1 1 2 b. –1.75, 1 1 , –1.656 2 d. 1 1 , –1.656, –1.75 2 ____ 39. Add. Estimate to check whether the answer is reasonable. 31.364 + 21.603 a. 52.967 c. 5.2867 b. 5.2967 d. 52.867 ____ 40. Subtract. Estimate to check whether the answer is reasonable. 60.123 18.179 a. 78.202 c. 41.944 b. 78.302 d. 41.954 ____ 41. Multiply. Estimate to check whether the answer is reasonable. 0.88 • 17 a. 1.506 c. 1.496 b. 15.06 d. 14.96 ____ 42. Multiply. Estimate to check whether the answer is reasonable. 27.6 • (–11.5) a. –317.3 c. –31.73 b. –317.4 d. –31.74 ____ 43. Divide. Estimate to check whether your answer is reasonable. 29.9 (–23) a. –1.3 c. 52.9 b. –1.387 d. –0.769 ____ 44. Divide. Estimate to check whether the answer is reasonable. 23.184 (–8.28) a. –2.8 c. 2.8 b. –0.28 d. 28 ____ 45. Divide. Estimate to check whether the answer is reasonable. 52 3.25 a. –160 c. 1.6 b. 16 d. –16 ____ 46. Multiply. Write the answer in simplest form. 8 1 3 a. 24 b. 1 24 c. 24 d. 8 3 ____ 47. Multiply. Write the answer in simplest form. 2 5 3 7 a. 14 15 c. 6 35 b. 2 35 d. 6 5 ____ 48. Multiply. Write the answer in simplest form. 3 1 37 a. 12 c. 3 1 2 2 7 b. 7 288 d. 41 1 7 ____ 49. Divide. Write the answer in simplest form. If the quotient is greater than 1, write the answer as an improper fraction. 2 ÷ 5 a. 1 5 c. 2 25 b. 25 2 d. 2 1 2 ____ 50. Divide. Write the answer in simplest form.If the quotient is greater than 1, write the answer as a mixed number. 10 3 1 11 ÷ 4 a. 2 11 c. b. 1 19 44 d. 6 11 28 44 63 ____ 51. Perform the following operation, and then simplify, if possible. a. c. 5 8 3 8 b. d. 5 16 5 8 ____ 52. Perform the following operation, and then simplify, if possible. a. c. 2 15 5 18 b. 1 18 d. 5 6 ____ 53. Add the mixed numbers.Write the answer as a mixed number in simplest form. 1 5 93 + 38 a. 12 11 12 c. 28 3 11 b. 12 23 24 d. 5 2 11 ____ 54. Subtract the mixed numbers.Write the answer as a mixed number in simplest form. 2 3 37 – 35 a. 9 35 c. 11 12 b. 11 35 d. 2 1 2 ____ 55. Write 8% as a fraction in simplest form. a. 0.08 c. 25 2 b. 1 2 25 d. 2 25 ____ 56. Write 14% as a decimal. a. 7.14 b. 0.14 c. 1.4 d. 7 50 ____ 57. Write the decimal 0.56 as a percent. a. 5.6% b. 0.0056% ____ 58. Write the fraction ____ 59. ____ 60. ____ 61. ____ 62. 3 4 c. 56% d. 14 % 25 as a percent. a. 0.75% c. 133.33% b. 0.75 d. 75% Use a fraction to estimate 18% of 98. a. 24 c. 2,000 b. 30 d. 20 Find 95% of 195. a. 185.25% c. 18,525 b. 205.26 d. 185.25 27 is what percent of 30? If necessary, round your answer to the nearest tenth of a percent. a. 111.1% c. 0.9% b. 1.1% d. 90% 48 is 30% of what number? If necessary, round your answer to the nearest tenth. a. 4.9 c. 160 b. 62.5 d. 1.6 Short Answer 63. The floor of a house is 80% covered by carpeting. a. Write the percent of the floor covered by carpeting as a decimal. b. Write the percent of the floor covered by carpeting as a fraction in its simplest form. 64. Consider the numbers 5 , 5.2, 5.02, 5 , and 5.333. a. b. Order the numbers from least to greatest. Write each of the fractions as a decimal, and each of the decimals as a fraction in simplest form. 65. Explain how to write 40% as a fraction in simplest form. Essay 66. Assume you know that a hot-air balloon is currently inflated with a certain amount of air and that the amount is a percent of the total amount required to inflate the balloon. Explain how you would determine the total amount of air required to inflate the balloon. 67. Suppose you had money in savings accounts at two different banks. If the amount of money in the first account is greater than the amount of money in the second account, can you assume that the first bank pays a higher interest rate? If not, what information would you need to determine which bank pays the higher interest rate? 68. If a tree grows during the course of a year, is its percent change an increase or a decrease? Explain how you would determine the percent change. Fractions, Decimals, and Percents Answer Section MULTIPLE CHOICE 1. ANS: C Expand the digits of the decimal. For example, given the number 3.141, you will have 3 + 0.1 + 0.04 + 0.001. KEY: decimal NOT: /A/Is this number mathematically the same as the original? /B/Do you need to add a decimal point? /C/Correct! /D/Are your leading zeros correct? 2. ANS: D Example: Given the number 3.141, you will have 3 + 0.1 + 0.04 + 0.001. KEY: decimal NOT: /A/Should the last digit be in the thousandths place or the ten-thousandths place? /B/Should the first digit be in the tens place or the ones place? /C/Is the decimal in the correct place? /D/Correct! 3. ANS: B Is there a number before the decimal? If so, write this number in word form. Place the word and between the whole number portion and the decimal portion of the number. Write the numbers following the decimal in words. Determine how many decimal places are present. Write the corresponding word for the decimal place. KEY: decimal NOT: /A/Is there a number before the decimal point? /B/Correct! /C/Check the place value of your decimal. /D/Is there a number before the decimal point? 4. ANS: A Working from left to right, compare the digits in each place to determine the order of the decimals. KEY: decimal, compare, order NOT: /A/Correct! /B/Compare each decimal place, working from left to right./C/Are you working from left to right? /D/Are you comparing the proper numbers? 5. ANS: C Multiply the two numbers. To determine the placement of the decimal point in the answer, count the number of decimal places in the two numbers being multiplied. In the answer, place the decimal point that many places from the right. KEY: decimal, multiplication NOT: /A/Should you add the numbers? /B/Did you count the decimal places in the problem to determine the decimal-point placement in the answer? /C/Correct! /D/How many combined decimal places are in the two numbers being multiplied? 6. ANS: B Divide as you would with whole numbers, and place the decimal point in the quotient directly above the decimal point in the dividend. KEY: decimal, division NOT: /A/Did you place the decimal point correctly in your answer? /B/Correct! /C/Did you place the decimal point correctly in your answer? /D/Should you subtract? 7. ANS: B To divide decimals, multiply the divisor and the dividend by the same power of ten to remove the decimal point from the divisor. Place the decimal point in the quotient directly above the decimal point in the dividend. KEY: decimal, division NOT: /A/Is your decimal point placed properly? /B/Correct! /C/Is your decimal point far enough to the left? /D/Are you dividing by the correct number? 8. ANS: A If there is a number to the left of the decimal, write that as the whole number. Write the decimal part as a fraction over 100, and simplify. KEY: decimal, fraction, mixed number NOT: /A/Correct! /B/Are you sure about the whole number part of the answer? /C/Should the digits after the decimal point be the denominator? /D/Is this an exact answer, or did you round to just one decimal place? 9. ANS: B To write a mixed number as a decimal, keep the whole number, and divide the numerator by the denominator for the part to the right of the decimal point. KEY: fraction, decimal NOT: /A/How do you write a fraction as a decimal? /B/Correct! /C/Should you add all of the digits? /D/Should you multiply all of the digits? 10. ANS: B Write all of the numbers as decimals with the same number of places. Order the numbers from least to greatest by comparing the digits from left to right. KEY: fraction, decimal, compare, order NOT: /A/Correct! /B/Does the problem ask for the numbers to be ordered from greatest to least? /C/Did you write each of the numbers as a decimal before trying to compare them?/D/Did you write each of the numbers as a decimal with the same number of places so you could compare them? 11. ANS: C Multiply or divide the numerator and denominator by the same nonzero number. KEY: equivalent fraction NOT: /A/Are these two fractions equal to each other? /B/Did you multiply or divide both the numerator and denominator by the same number? /C/Correct! /D/Did you confuse the numerator and denominator by inverting the fractions? 12. ANS: C Multiply both the numerator and the denominator of the first fraction by the same number to obtain the second fraction. KEY: fraction, equivalent fraction, multiplication, division NOT: /A/Did you multiply both the numerator and denominator by the same number to obtain the second fraction? /B/Did you find the factor used to obtain the other number in the new fraction? Use it to find this number as well. /C/Correct! /D/Can this number be the same as it was in the first fraction if the other number has changed? 13. ANS: A If the GCF of both the numerator and the denominator is 1, then the fraction is already in simplest form. Otherwise, divide the numerator and denominator by the GCF to simplify it. KEY: fraction, simplest form NOT: /A/Correct! /B/Did you divide the numerator by the same number you used to simplify the denominator? /C/This fraction is equivalent, but is it the simplest form? /D/Did you divide the denominator by the same number you used to simplify the numerator? 14. ANS: A First write the fractions so that they have a common denominator. Then order them from least to greatest by comparing the numerators. KEY: fraction, order NOT: /A/Correct! /B/Did you compare the numerators of the fractions after writing them with common denominators? /C/Did you put the fractions in order from least to greatest?/D/Did you write the fractions with common denominators to compare them? 15. ANS: B Subtract the numerators of the fractions and write the result over the common denominator. Then subtract the whole numbers, and simplify if necessary. KEY: fraction, like fraction, mixed number, subtraction NOT: /A/Did you remember the rules for subtracting fractions? Subtract the numerators and keep the denominator. /B/Correct! /C/Did you subtract the fractions or add them? /D/Did you remember that you keep the common denominator when subtracting fractions? 16. ANS: D Write the whole number as a fraction with a denominator of 1. Multiply numerators and denominators. Write the answer in simplest form. KEY: fraction, multiplication NOT: /A/Did you write the whole number as a fraction over 1 and then multiply the numerators and the denominators? /B/Did you multiply the whole number by the fraction, or did you add them together? /C/Did you multiply the whole number by the numerator, or did you add them together? /D/Correct! 17. ANS: C Multiply the fractions by multiplying the numerators and multiplying the denominators, and then simplify if possible. KEY: fraction, multiplication NOT: /A/Is this how you multiply fractions? /B/Are you supposed to be dividing the fractions?/C/Correct! /D/Are you supposed to be adding the fractions? 18. ANS: B First write any mixed numbers as improper fractions, and then multiply the numerators and multiply the denominators. Simplify if possible. KEY: fraction, mixed number, multiplication NOT: /A/Are you supposed to be adding the fractions? /B/Correct! /C/Are you performing the correct operation? /D/Is this how you multiply fractions? 19. ANS: C First write the mixed numbers as improper fractions, and then multiply the numerators and multiply the denominators. Simplify if possible. KEY: mixed number, multiplication NOT: /A/Are you supposed to be adding the fractions? /B/Are you performing the correct operation?/C/Correct! /D/Is this how you multiply fractions? 20. ANS: C To divide fractions, first write any mixed numbers as improper fractions, and then multiply the first fraction by the reciprocal of the second fraction. Simplify if possible. KEY: reciprocal, fraction, division NOT: /A/Did you use the reciprocal of the right fraction? /B/Are you using the reciprocal at the right time? /C/Correct! /D/Are you performing the correct operation? 21. ANS: B To add or subtract the fractions, first find the lowest common denominator and rewrite them as equivalent fractions. Then add or subtract the numerators, and place the result over the common denominator. KEY: fraction, addition, subtraction, unlike denominators NOT: /A/Did you calculate your denominator correctly? /B/Correct! /C/Did you calculate the equivalent fractions properly? /D/Did you calculate your numerator correctly? 22. ANS: A Add or subtract the fractions by finding the lowest common denominator and rewriting them as equivalent fractions. Add or subtract the fractions and then the whole numbers. Simplify. KEY: mixed number, addition, subtraction NOT: /A/Correct! /B/What must you do to the denominators when adding or subtracting fractions? /C/Did you calculate your denominator correctly? /D/Did you calculate your numerator correctly? 23. ANS: C First find the lowest common denominator, and rewrite the fractions as equivalent fractions. Then subtract 1 from the whole number of the first mixed number, and add a fraction equivalent to 1 to the fractional part of the first mixed number to make the first numerator greater than the second. Finally subtract the whole numbers and then the fractions. KEY: mixed number, rename NOT: /A/Did you find a common denominator? /B/Did you find a common denominator? /C/Correct! /D/Did you calculate your denominator correctly? 24. ANS: D Place the percent in the numerator of a fraction with 100 in the denominator. Then simplify the fraction. KEY: percent, fraction NOT: /A/Did you find the decimal value or the fraction? /B/What number should be placed in the numerator of the fraction? /C/Which number goes in the numerator of the fraction? /D/Correct! 25. ANS: A Divide the percent by 100. KEY: percent, decimal NOT: /A/Correct! /B/What number should you divide by? /C/Is this in decimal form? /D/What number should you divide by? 26. ANS: B Multiply the decimal by 100. KEY: percent, decimal NOT: /A/Should this be a fraction? /B/Correct! /C/What number do you multiply by? How many places do you move the decimal point?/D/Do you multiply or divide in this case? Which direction do you move the decimal point? 27. ANS: C Divide the numerator by the denominator, multiply the result by 100, and place a % symbol behind the answer. KEY: percent, fraction NOT: /A/Should you divide the numerator by the denominator or the denominator by the numerator? /B/How many places should you move the decimal point? /C/Correct! /D/Did you forget to multiply by some number? 28. ANS: B Multiply 35 by 20, then divide by 100. KEY: percent, multiplication NOT: /A/Did you forget to divide the percent by 100? /B/Correct! /C/Should you multiply the number by the decimal form of the percent? /D/What is the decimal equivalent of the percent? 29. ANS: B The point is between –2 and –1. Approximate where on the number line the fraction would be. KEY: decimal, fraction, number line, rational number NOT: /A/Decide between which two integers the fraction would be. /B/Correct! /C/Decide between which two integers the fraction would be. /D/Pay attention to the fraction's sign. 30. ANS: A The point is between 1 and 2. Approximate where on the number line the decimal would be. KEY: decimal, fraction, number line, rational number NOT: /A/Correct!/B/Pay attention to the sign. /C/Decide between which two integers the decimal would be. /D/Decide between which two integers the decimal would be. 31. ANS: D To find an equivalent fraction, multiply or divide both the numerator and the denominator by the same number. KEY: equivalent, fraction NOT: /A/Did you multiply or divide the numerator and the denominator by the same number? /B/This is the reciprocal of the fraction, not an equivalent fraction. /C/This is the opposite of the fraction, not an equivalent fraction. /D/Correct! 32. ANS: D To find an equivalent fraction, multiply or divide both the numerator and the denominator by the same number. KEY: equivalent, fraction NOT: /A/Did you multiply or divide the numerator and the denominator by the same number?/B/This is the reciprocal of the fraction, not an equivalent fraction. /C/This is the opposite of the fraction, not an equivalent fraction. /D/Correct! 33. ANS: B Divide the numerator by the denominator. Use the quotient and remainder to write the mixed number. KEY: convert, improper fraction, mixed number NOT: /A/Divide the numerator by the denominator. Use the quotient as the whole number, and put the remainder over the denominator. /B/Correct! /C/Divide the numerator by the denominator. Use the quotient as the whole number, and put the remainder over the denominator. /D/Divide the numerator by the denominator. Use the quotient as the whole number, and put the remainder over the denominator. 34. ANS: A Multiply the denominator and whole number, and then add the numerator. Write the result over the denominator. KEY: convert, improper fraction, mixed number NOT: /A/Correct! /B/Multiply the denominator and the whole number, and then add the numerator. Put this result over the original denominator. /C/Multiply the denominator and the whole number, and then add the numerator. Put this result over the original denominator. /D/Multiply the denominator and the whole number, and then add the numerator. Put this result over the original denominator. 35. ANS: C To write a fraction as a decimal, divide the numerator by the denominator. KEY: convert, decimal, fraction, rational number NOT: /A/Be careful when dividing. /B/Divide the numerator by the denominator. /C/Correct! /D/Divide the numerator by the denominator. 36. ANS: D Use the place value of the decimal part of the number to calculate the fraction. For example, 6.25 is 6 and since the decimal part of 6.25 goes out to the hundredths place. Simplify the fraction to obtain . KEY: convert, decimal, fraction, rational number NOT: /A/This decimal number does not go out to the thousandths place. /B/The fraction part is not in simplest form. /C/Pay attention to the sign. /D/Correct! 37. ANS: D To compare decimals, line up the decimal points and compare digits from left to right until you find the place where the digits are different. Remember to consider a negative sign. KEY: compare, decimal NOT: /A/Line up the decimal points and check from left to right until you find the place where the digits are different. If the numbers are negative, remember that the number closer to zero on the number line is the greater number. /B/Line up the decimal points and check from left to right until you find the place where the digits are different. If the numbers are negative, remember that the number closer to zero on the number line is the greater number. /C/Line up the decimal points and check from left to right until you find the place where the digits are different. If the numbers are negative, remember that the number closer to zero on the number line is the greater number. /D/Correct! 38. ANS: C Write all of the numbers as decimals having the same number of places. KEY: compare, decimal, fraction, order NOT: /A/Write all of the numbers as decimals having the same number of places. /B/Correct! /C/These numbers are in order from greatest to least. /D/Write all of the numbers as decimals having the same number of places. 39. ANS: A Line up the decimal points. Add. Estimate both numbers, and add to check whether your answer is reasonable. KEY: addition, decimal NOT: /A/Correct! /B/Check the position of your decimal point. /C/Check your addition and the position of the decimal point. /D/Check your addition. 40. ANS: C Line up the decimal points. Subtract. Estimate both numbers and subtract to check if answer is reasonable. KEY: decimal, subtraction NOT: /A/Did you perform the correct operation? /B/Did you perform the correct operation? /C/Correct! /D/Check your subtraction. 41. ANS: D Multiply the numbers. The number of decimal places should equal the sum of the decimal places in both factors. KEY: decimal, integers, multiplication NOT: /A/Check for an error in your multiplication, and check the position of the decimal point. /B/Is there a mistake in adding the numbers in the multiplication process? /C/What is the total number of decimal places in the two factors? Correct the position of the decimal point. /D/Correct! 42. ANS: B Multiply the numbers. The number of decimal places should equal the sum of the decimal places in both factors. KEY: decimal, multiplication NOT: /A/Check for errors in your multiplication. /B/Correct! /C/Check for errors in your multiplication, and check the position of the decimal point. /D/What is the total number of decimal places in the two factors? Correct the position of the decimal point. 43. ANS: A Divide the decimal by the integer. The decimal place is placed directly above the decimal point that is under the division symbol. Estimate to check whether your answer is reasonable. KEY: decimal, division, integers NOT: /A/Correct! /B/Check your math./C/The correct operation is division. /D/Which number is the dividend, and which is the divisor? 44. ANS: A Multiply both numbers by the least power of ten that will make the divisor an integer. The decimal point for the answer will then go directly above the decimal point that is under the division symbol. KEY: decimal, division NOT: /A/Correct! /B/Check your decimal point position. /C/Check the sign of your answer. /D/Check your decimal point position and the sign of your answer. 45. ANS: B Multiply both numbers by the least power of ten that will make the divisor an integer. The decimal point for the answer will then go directly above the decimal point that is under the division symbol. KEY: decimal, division, integers NOT: /A/Is your sign correct? Check the position of your decimal point. /B/Correct! /C/Check the position of your decimal point. /D/Is your sign correct? 46. ANS: D Write the integer as a fraction with 1 as the denominator. Multiply, then simplify. 1 3 = 8 3 KEY: fraction, multiplication NOT: /A/Pay attention to your sign. /B/Do not divide the integer. /C/Do not divide the fraction. /D/Correct! 47. ANS: C Multiply the numerators and the denominators. Then simplify. KEY: fraction, multiplication NOT: /A/Are you performing the correct operation? /B/Did you multiply the numerator of one fraction times the numerator of the other? /C/Correct! /D/Did you multiply the denominator of one fraction times the denominator of the other? 48. ANS: A Change any mixed numbers to improper fractions, and then multiply. Simplify the answer. KEY: mixed number, multiplication NOT: /A/Correct! /B/Do you want to multiply by the reciprocal of the first or second fraction? /C/Is your numerator and denominator correct? /D/Do you want to divide the fractions? 49. ANS: D Multiply the first fraction by the reciprocal of the second. KEY: division, fraction NOT: /A/Are you performing the correct operation? /B/Division is the same as multiplying by what? /C/Are your numerator and denominator correct? /D/Correct! 50. ANS: A Write any mixed numbers as improper fractions, and then multiply the first fraction by the reciprocal of the second. Simplify. KEY: division, mixed number NOT: /A/Correct! /B/Are you performing the correct operation? /C/Division is the same as multiplying by what? /D/Are your numerator and denominator correct? 51. ANS: A Add or subtract the numerators and keep the common denominator. KEY: addition, fraction, like denominators, subtraction NOT: /A/Correct! /B/Should you add the denominators? /C/Pay attention to the signs. /D/Pay attention to the operation being performed. 52. ANS: C Find the common denominator of the two fractions and then add or subtract. KEY: addition, fraction, subtraction, unlike denominators NOT: /A/Pay attention to the signs. /B/Pay attention to the operation being performed. /C/Correct! /D/Should you add the denominators? 53. ANS: B Add the integers and add the fractions. KEY: addition, mixed number NOT: /A/Watch your addition. /B/Correct! /C/Should you add the denominators? /D/Should you add the denominators? 54. ANS: B Write the mixed numbers as improper fractions. Then rewrite the fractions with common denominators and subtract. Simplify the result. KEY: mixed number, subtraction NOT: /A/Watch your subtraction. /B/Correct!/C/Should you add the denominators? /D/Should you subtract the denominators? 55. ANS: D Place the percent in the numerator of a fraction, put 100 in the denominator, and simplify the resulting fraction. KEY: fraction, percent NOT: /A/You found the decimal value, not the fraction. /B/Any percent less than 100 will result in a fraction less than 1. /C/Which number goes in the numerator of the fraction? /D/Correct! 56. ANS: B Divide the percent by 100. This is the same as moving the decimal point two places to the left. KEY: decimal, percent NOT: /A/Which number goes in the numerator of the fraction? /B/Correct! /C/How many places do you move the decimal point when converting from a percent to a decimal? /D/Is this in decimal form? 57. ANS: C Multiply the decimal by 100 and add the % symbol. This is the same as moving the decimal point two places to the right. KEY: decimal, percent NOT: /A/By what number do you multiply?/B/Which direction do you move the decimal point when converting from a decimal to a fraction? /C/Correct! /D/Should your answer be a fraction? 58. ANS: D Divide the numerator by the denominator, multiply the result by 100, and put the % symbol after the answer. KEY: fraction, percent NOT: /A/How do you convert a decimal to a percent? /B/Be sure to write the answer as a percent, not a decimal. /C/How do you convert a fraction to a decimal? /D/Correct! 59. ANS: D Find a fraction that is close in value to the percent. Change the number to a compatible number that is easy to use. Multiply the fraction by the compatible number. KEY: estimate, fraction, percent NOT: /A/Be careful when deciding which fraction and which compatible number to use. /B/Use compatible numbers that are close to the exact numbers. /C/Remember you are dealing with percentages. /D/Correct! 60. ANS: D Method 1: Use the decimal equivalent of the percent to solve this problem. 0.95 195 = 185.25. Method 2: Set up and solve the proportion . KEY: percent NOT: /A/Are you supposed to find a number or a percent? /B/Check how you setup your proportion./C/Be careful when writing a percent as a decimal or when solving a proportion. /D/Correct! 61. ANS: D Set up the proportion , and solve for n. KEY: percent NOT: /A/Check the setup of your proportion. /B/Which numbers go in the denominators of the fractions in the proportion? /C/Did you forget to factor in 100? /D/Correct! 62. ANS: C Use a proportion. Solve for x. KEY: percent NOT: /A/Start by representing the percent as a decimal. /B/Check the setup of your equation. /C/Correct! /D/Did you forget to represent the percent as a decimal? SHORT ANSWER 63. ANS: a. 0.80 b. KEY: percent 64. ANS: a. 5.02, 5.2, 5 , 5.333, and 5 b. 5 = 5.4 5.2 = 5 5.02 = 5 5 = 5.25 5.333 = 5 KEY: compare, convert, decimal, fraction, order, Performance Assessment 65. ANS: Solution: Write the percent as a fraction with a denominator of 100: Simplify the fraction: KEY: fraction, percent ESSAY 66. ANS: Since you know the percent of air and the amount of air, set up a proportion: Substitute the values you know and solve for the TOTAL air. KEY: percent, Performance Assessment 67. ANS: No. You have to know how much money is currently in each account, how much money was originally deposited in each account, and how long ago it was deposited. KEY: interest, simple interest 68. ANS: Percent increase. Subtract the tree’s original height from its new height. Divide the difference by the original height and multiply by 100 to get the percent change. KEY: percent change, percent decrease, percent increase